Arandom sample of 116 lightning flashes in a certain region resulted in a sample average radar echo duration of 0.81 sec and a sample standard deviation of 0.33 sec. calculate a 99% (two-sided) confidence interval for the true average.

Ou have a 20-ounce bottle of juice. you pour out 14 of the bottle to share with a friend. if you pour out 3 ounces for yourself, what fraction of the 20 ounces will be left in the bottle? clear check 35 25 12 1320

Which of the following points is collinear with (-2,1) and (0,3)

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60